Blast-heating apparatus.



No. 879,302. PATENTED FEB. 18, 1908.

J. W. NESMITH. BLAST HEATING APPARATUS.

APPLICATION FILED APR. 3, i905.

2 SHEETS-SHEET l.

1NVENTOR. J. W. NESMITH.

ATTORNEY.

No. 879,302. PATENTED FEB. 18, 1908. J. w. NESMITH. BLAST HEATING APPARATUS.

APPLICATION FILED APR. 3, 1905.

2 SHEETS-SHEET 2.

m m N W W JW NESMITH.

--stove or heating chamber, havebeen em- UNIT STATES V PATENT OFFICE.

JOHN W. NESMITH, or

DENVER, COLORADO, ASSIGNOB TO COLORADO IRON WORKS COMPANY, OF DENVER, COLORADO.

BLAST-HEATING APPARATUS..

Specification of Letters Patent.

Patented Feb. iefioos.

To all whom it may concern:

[Be it known that I, JOHN W. NESMITH, a citizen of the United States, residing at the city and county of Denver and'Stateof Colo rado; have invented certain new and useful lmirovements in Blast-Heating Apparatus; an I do declare thefollowingto be a full,

clear, and exact description of the invention;

such as will enable others skilled in theart to which 'it' appertains to make and use the same, reference being had to the accompanying drawings, and t0 the letters and figures of re e rence marked thereon, which form a part of this specification.

My invention relates to im rovernents apparatus for heating an air last preparatory to its delivery to the furnace as a blastfurnace where it is to be employed. It is well known that it is desirable to heat the air' blast in furnaces of this character, that is to say where a high degree of heat'is required in order to melt or fuse the ore or other material in the furnace.

Heretofore so far as I- amawa're, conduits composed of U-pipe members, located in a ployed the said conduits having plain in terior surfaces. As these conduits are of considerable size, it has been found impossible to properly (heat the entire volume of air passing therethrough, since. while the air immediatel adjacent the Wall of the conduit is proper y heated, the air occupying the central part of'the conduit remains comparatively cool.

The object of my resent invention is to overcome this difiicu ty and to this end, instead of makin the inner Walls of the conduits smooth, provide the'same withinteriorly-projectingjbeads rplatespreferably radially dis osed whereby the heating surface or area wit which the blast comes in contact,

is greatly increased. These radial plates or beads, may be of any desired width.

Having briefl outlined my improved construction as wel as the function it is intended to-perf0rm, I will proceed todescribe the same in detail reference bein made to the,

accom anying drawing in whic, isillustrated an em odiment thereof.

In this drawing, Figure 1 is a top plan view of a.U-shaped member of the blast-heating conduit, provided with my improvements. Fig. 2 is a side'elevation of the same. Fig. 3 is a cross section taken through one of the Application filed April 3. 1905. i Serial No. 253.612.

'rnembers shown on a larger scale. Fig. 4- 1s a section taken through the blast heating apparatus showing the conduit composed of the U-shaped members in elevation.

The same reference characters indicate the same partsin all the views.

Let the numeral 5 designate the ordinary 'blast heating apparatus composed of a fire box 6, a heating chamber 7, a stack 8, a blast inlet 9, a conduit 10 and an outlet 12 for the hot'blast. This mechanism is of ordinary construction. Within the chamber 7 is the blast conduit 13 composed of the U-sha ed members 14 shown in Figs. 1 and 2. no end of this conduit 13 communicates with the blast inlet 9, while its op osite'extremity communicates with the hot last conduit 10.

. 'As shown in the drawing the conduit is composed of'but two U shaped members. Ordinarilythese blast heating conduits are of considerablelength. The constructionshown in the drawing, however, is suflicient to answer the purposes of my resent invention. Usuallya number of con uits are arranged side by side within thev heating chamber. This feature, however, is not material so far as my present purposes are concerned.

,As heretofore outlined the feature. of my invention which distinguishes it from an blast conduits'of ordinary construction, is

the interiorly protecting radial plates or beads 15 which as s own in the drawingare formed integral with the straight or vertical parallel portions of each U-shaped member. As shown in the drawing there is a considerable numberofthese radial plates. The

, exact number, however, is not material ex- ,in Fig. 3 of the drawing, is believed-about right under ordinary circumstances though 0 course the inventlon is not limited to any precise number'of these plates.

In the use ofa blast heating apparatusof this character, attention is called to the fact that the blast is introduced to the conduit ,13

travel in a direction opposite the travel ofv the hot ases or products of combustion through t e heating chamber.

The object of this is, to utilize to the fullest extent possible the heat from the firebox, and this efli ciency is best obtained bycausing the air to travel from the coldest to the hottest part of the heating chamber, whereby the temperature to which the air is subjected, is continually rising thus maintaining a constant differential of considerable magnitude between the blast and the temperature of the chamber.

Having thus described my invention, what I claim is:

A blast heating conduit composed of U- sha ed members, the arallel portions of eac 1 U-shaped member being provided with radially disposed ribs projecting into the interior only thereof, and the curved portions having both the exterior andinterior surfaces thereof smooth. In testimony whereof 'I affix my signature in presence of two witnesses.

JOHN W. NESMITI-I.

Witnesses:

R. E, GIBBS, C. OB. BERRY. 

